Pliable molding tool



Filed Nov. 9, 1964 Z m m E R A w m 5 w/ I 1 n fimfim h n n u u u n n nUnited States Patent Ofitice 3,316,588 Patented May 2, 1967 3,316,588PLIABLE MOLDING TOOL Steve Vezirakis, Vancouver, Wash., assignor to DonsSports Systems, Inc., a corporation of Washington Filed Nov. 9, 1964,Ser. No. 409,771 2 Claims. (Cl. Iii-5.1)

This invention relates to improvements in bowling balls and moreparticularly relates to an improved bowling ball and method andapparatus for forming the finger holes in bowling balls.

Bowling balls have heretofore been drilled to form finger grips for theball, the finger holes being sized and spaced to receive the thumb,middle finger and ring finger of the bowler and to comfortably fit thespread of the bowlers fingers.

The balls many times are not drilled for the hand of a particular bowlerand where the bowler does not have his own ball, he will select a ballin which the hole size and spread approximates the hand of the bowler.

Even where the ball is drilled to the hand of the bowler, it isdifiicult to obtain an exact fit and the finger holes are frequently tootight or too loose and the walls of the finger holes are cylindricalthroughout their length and do not provide suificient gripping surfaceto give the average bowler the required control of the ball.

It is, accordingly, the principal object of the present invention toremedy the foregoing deficiencies by providing a new and improved formof bowling ball in which the finger holes are formed to generallyconform to the fingers of the bowler, to increase the finger grippingaction on the ball with the resultant added comfort to the bowler andincreased control of the ball.

A further object of the invention is to provide an improved form ofbowling ball having molded finger holes in the ball forming permanentfinger holes conforming to the fingers of the bowler.

A further object of the invention is to improve upon the bowling ballsheretofore in use by molding finger inserts in the ball to form anintegral part of the ball and by so molding the inserts as to generallyconform to the forms of the fingers holding the ball, to increase thegripping action and control of the ball and accommodate the ball to movesmoothly off the fingers in the act of throwing the ball.

A further object of the invention is to provide a tool or pattern forforming the finger grip inserts molded in bowling balls and made from apliable material accommodating ready removal of the insert from thesolid mold, by the pulling on and contraction of the insert.

Still another object of the invention is to provide an improved methodfor forming the finger holes in bowling balls to size, in which thefinger holes are molded in the balls by a compound different from thematerial from which the ball is made and forming permanent fingerinserts in the balls generally conforming to the fingers of the bowler.

These and other objects of the invention will appear from time to timeas the following specification proceeds and with reference to theaccompanying drawings wherein:

FIGURE 1 is a generally diagrammatic view of a bowling ball;

FIGURE 2 is a view in side elevation of a molding tool or patternconstructed in accordance with the principles of the present inventionfor forming the finger holes in the bowling ball;

FIGURE 3 is a view of the pattern shown in FIGURE 2 with the patternturned 90 in a clockwise direction from the position shown in FIGURE 2,in order to show certain finger conformations of the pattern not shownin FIGURE 2;

FIGURE 4 is a fragmentary sectional view taken through the thumb hole ofa bowling ball with molding compound in the thumb hole, and illustratinga step in the molding of the thumb hole in the bowling ball;

FIGURE 5 is a fragmentary sectional view somewhat similar to FIGURE 4but showing the pattern in position in the thumb hole of the bowlingball and displacing the molding compound upwardly into the hole; and

FIGURE 6 is a fragmentary sectional view taken through the thumb hole ofa bowling ball with the molding compound hardened and the mold removed.

In the embodiment of the invention illustrated in the drawings, I haveshown in FIGURES 2 and 3 a molding tool or pattern 10 having a generallycylindrical head 11 adapted to be positioned outside of the periphery ofthe ball, when molding an insert therein and to form a gripping surfaceto accommodate withdrawal of the pattern from the mold. The pattern 10is made from a flexible material to stretch or contract and reduce thecross-sectional area thereof upon the exertion of a pulling forcethereon, to accommodate removal of the pattern from the mold. Thepattern may be made from rubber, vinyl rubber, plastisols, rubber-likeepoxys, urethane resins, elastomeric plastics, silicone rubber and likeflexible materials. A material which has been found to be satisfactoryfor the pattern is known to the trade as HIV silicone rubber. This willwithstand the temperatures and pressures of molding and accommodateready contraction and withdrawing of the pattern from the mold, whenhardened.

The pattern 10 has a reduced diameter stem or finger portion 12extending therefrom and formed generally to the contour of the finger,but longer than the average finger, so one pattern of a selecteddiameter may be used for many different lengths of fingers.

The stem 12 has a generally cylindrical wall portion 13 extending forsubstantially the length thereof and having an inwardly taperedflattened end portion 15, converging toward the center of the stem. Theopposite side of the stem 12 from the tapered portion 15 has a recessedportion 16 generally conforming to the finger and flat in trans-versesection and of an arcuate form in side elevation. The recessed portion16 terminates into a ridge 17, shown as having an outer surface ofsubstantially the diameter of the cylindrical portion 13. The ridge 17in turn terminates into an inwardly curved transversely flattenedconverging portion 19, shown as being generally arcuate in form, of thegeneral form of the end of the finger, and meeting the tapered portion15 in a generally uniformly curved end portion 26 to one side of thecenter of the pattern as shown in FIGURE 2. The portions 15 and 19,therefore, generally simulate the nail and portion of the thumb behindthe nail.

The particular tool or pattern 10 herein shown is for the thumb. Thepatterns for the middle and ring fingers may be similarly formed,although longer and smaller in diameter than the pattern for the thumb.A large range of pattern sizes for the thumbs and fingers may be stockedto provide the required finger patterns for an individual bowler,although the patterns may 'be made to order if desired.

In FIGURE 1, I have diagrammatically shown a bowling ball 21 having athumb hole 22 and finger holes 23, 23. The thumb and finger holes aredrilled in a drill press by setting the ball in a fixture and arrangingthe ball for drilling the holes to a required pitch, as determined by agauge for the fixture and drill press (not shown). Where the gauge maybe set to zero for drilling of a thumb hole, the hole will be a radialhole and its center will intersect the center of the ball. The fingerholes are usually drilled with a forward pitch, a inch forward pitchbeing a standard angle. With such a pitch the centers of the fingerholes intersect radial lines at distances of inch from the center of theball.

It is, of course, understood that the pitches of the thumb and fingerholes may be reverse pitches as well as a forward pitch and may even beside pitches, in accordance with the size and shape of the bowlers hand.

In forming a thumb hole, as shown in FIGURES 4, 5 and 6, the diameter ofthe thumb of the bowler is measured one size larger than the thumbknuckle to provide a comfortably loose fit of the thumb in the thumbhole. The measure of the length of the thumb of the bowler is also takenand the angle of the bowlers release point is determined by having thebowler grip a ball having a thumb hole 22 and finger holes 23, 23drilled oversize, and slowly drawing the bowlers thumb out of the thumbhole. This will accurately determine the release of the bowlers thumb.Two parallel lines 25 conforming to the angle of release are then drawnon the surface of the ball as a visual guide to determine the angle atwhich the pattern is to be inserted.

In drilling the ball to accommodate the molding of the thumb holetherein, the ball is set up on a drill press and fixture and properlypitched in the fixture, a drill bit is then selected larger than thesize of the hole to be molded. The drill bit may be 7 of an inch largerthan the largest diameter portion of the hole to allow the moldingcompound to settle and form a solid mold. Upon drilling of the hole 26,the top part of the ball is drilled at the pitch of the hole 26, tofor-m a large diameter hole 27 extending along the hole 26 coaxial withthe center thereof for substantially of an inch. All round edges andbevels are then cleaned from the hole to provide sharp edges throughoutthe hole and all dirt and material in the hole is cleaned out. Thesurface of the ball around the hole just drilled is also cleaned ofdirt. A plugging clay 29 may then be placed around the hole to preventthe molding compound from running over the outer surface of the ball.

The hole 26 may then be filled about one-half full of a pluggingcompound which may be a thermosetting plastic which will rigidly hardenover a period of time. One suitable material being an epoxy compoundwhich rigidifies upon setting and is known to the bowling ball repairtrade as Ball Plug. Another compound found to be suitable and commonlyused in the bowling trade is a compound known to the trade as Ball Mate.Where this compound is used, two parts of Ball Mate compound should becombined with one part Ball Mate hardener and mixed to insure uniformblending and then allowed to stand to eliminate all air bubbles in thecompound. This compound must be used within one hour from mixing;

Assuming the ball is properly drilled and the plugging clay 259 isplaced along the hole on the surface of the ball, a selected plasticplugging compound in a liquid state may then be poured into the holefilling the hole substantially half full, as indicated by referencecharacter 30, in FIG- URE 4.

A finger cot 31 generally conforming to the pattern is then placed overthe pattern and along the head 11 for a portion of the length thereof,to protect the pattern and facilitate the removal of the pattern whenthe compound hardens. The finger cot may be made from a thin plasticmaterial generally conforming to the form of the pattern which willeasily release the pattern when the compound is hardened. Any part ofthe finger cot sticking to the mold may readily be removed by long-nosedpliers and the like.

A finger cot being in place on the pattern, a mark 32 is made on theoutside of the finger cot in accordance with the length of the finger orthumb to gauge the depth at which the pattern is set into the hole.

The finger cot being in position on the pattern, the pattern and fingercot are then inserted in the hole 26 at the proper angle determined bythe thumb release lines 25-- 25. This will displace the molding compoundto surround the pattern and finger cot as shown in FIGURE 5. Where themolding compound is insufficient to come up to position slightly overthe top of the enlarged diameter portion of hole 27 as shown in FIGURE5, additional compound may be poured into the hole with the pattern 10held in place. The pattern being positioned in the correct angularrelation with respect to the ball, molding clay may be placed on thesurface of the ball around the clay 29 and engaged with the head of thepatternto steady the pattern during hardening of the compound, asindicated by reference character 3 I The hole being completely filledwith compound and the pattern being held in place by the molding clay33, the compound should now be allowed to dry. The drying period for thecompounds mentioned herein is approximately 12 hours and the temperatureof drying should not be under F. v

When the compound has hardened, the head 11 of the pattern may begripped by the hand and an outward pull on the pattern may be exerted.This will effect contraction or stretching of the pattern and thisstretching along with the finger cot covering the pattern in thehardened compound, will accommodate the pattern to be readily releasedwith a gentle pull. Any portion of the finger cot not coming out withthe pattern may then be removed.-

The clay 29 and 33 may then be removed and any excess portion of theplugging compound may be trimmed to provide an outer surface flush withthe peripheral surface of the ball.

A bevel may then be filed on the palm side of the thumb hole and thebeveled part of the hole may be sanded and buffed to provide a finishlike the finish on the periphery of the bowling ball.

It may be seen from the foregoing that I have provided a new andimproved form of bowling ball having finger holes generally conformingto the thumb, index finger and ring finger of the bowler, which areformed by pouring a plastic liquid into an oversize hole and bymoldingthe compound by a pattern generally conforming to the form of thefinger of the bowler and held at a selected angle with respect to thecenter of the ball, depending upon the hand of the bowler.

The ball may thus have finger holes formed as a part thereof accuratelyconforming to the fingers and span of the hand of the bowler and soformed as to facilitate the release of the ball and increase the contortand ability of the bowler to control the path of the ball.

It may further be seen that the finger holes form an in tegral part ofthe ball and the molding compound cannot be distinguished from thematerial from which the ball is made upon proper finish of the ball.

While I have herein shown and described one form in which the inventionmay be embodied, it may readily be understood that various modificationsand variations in the invention may be attained without departing fromthe spirit and scope of the novel concepts thereof.

I claim as my invention:

1. A tool for forming finger holes in bowling balls con-- forming to thefinger of the bowler comprising:

a solid pliable pattern for forming finger holes in a bowling balladapted to fit in a predrilled oversize finger hole in the bowling balland form a pattern for molding compound in the oversize hole, saidpattern having a generally cylindrical head on the outer end thereof,

a reduced diameter generally cylindrical wall portion extending fromsaid head for a portion of the length of said pattern and having ashallow flat concave recess on one side thereof locking the pattern tothe mold upon hardening of the molding compound,

a ridge at the inner end of said recess, and converting into a flattenedinwardly curved 5 convex portion in the general form of the end of thefinger behind the nail, said cylindrical Wall portion having an oppositeflattened portion generally simulating the nail portion of the thumb,and said head forming a hand grip adapted to be gripped by the hand tostretch and unlock the pattern for removal from its mold. 2. Thestructure of claim 1, wherein the pattern is made from silicone rubber.

References Cited by the Examiner UNITED STATES PATENTS Curteman 18-51Zahn. Sawyer. Policofi 18-5.1 Gillrnan 264-222 X James. Sterczek 264-222Borton et a1. MacDonald 273-63 Bednash 273-63 Williams. Chetirko 264-222WILLIAM J. STEPHENSON, Primary Examiner.

1. A TOOL FOR FORMING FINGER HOLES IN BOWLING BALLS CONFORMING TO THEFINGER OF THE BOWLER COMPRISING: A SOLID PLIABLE PATTERN FOR FORMINGFINGER HOLES IN A BOWLING BALL ADAPTED TO FIT IN A PREDRILLED OVERSIZEFINGER HOLE IN THE BOWLING BALL AND FORM A PATTERN FOR MOLDING COMPOUNDIN THE OVERSIZE HOLE, SAID PATTERN HAVING A GENERALLY CYLINDRICAL HEADON THE OUTER END THEREOF, A REDUCED DIAMETER GENERALLY CYLINDRICAL WALLPORTION EXTENDING FROM SAID HEAD FOR A PORTION OF THE LENGTH OF SAIDPATTERN AND HAVING A SHALLOW FLAT CONCAVE RECESS ON ONE SIDE THEREOFLOCKING THE PATTERN TO THE MOLD UPON HARDENING OF THE MOLDING COMPOUND,A RIDGE AT THE INNER END OF SAID RECESS, AND CONVERTING INTO A FLATTENEDINWARDLY CURVED CONVEX PORTION IN THE GENERAL FORM OF THE END OF THEFINGER BEHIND THE NAIL, SAID CYLINDRICAL WALL PORTION HAVING AN OPPOSITEFLATTENED PORTION GENERALLY SIMULATING THE NAIL PORTION OF THE THUMB,AND SAID HEAD FORMING A HAND GRIP ADAPTED TO BE GRIPPED BY THE HAND TOSTRETCH AND UNLOCK THE PATTERN FOR REMOVAL FROM ITS MOLD.